In a career spanning four decades, photographer Mick Rock has captured images of some of the great pop musicians of our time.

Those iconic photographs, now on display in Washington, include 1970s superstars David Bowie and Freddie Mercury, as well as current talents such as Bono, Lady Gaga and Janelle Monae.

Rock was born in London and became interested in photography as a student at Cambridge University in the late 1960s. He was taking classes in modern languages and literature but picked up a friend’s camera one day and started taking pictures of his buddies.

That led to a passion. Soon, a local band paid him to take a few pictures of them. And that, says Rock, "sort of triggered something.”

Shooting the 70s

His big break came in 1972, when he heard the album, “Hunky Dory,” by an unknown musician named David Bowie.

“There was one particular track called ‘Life on Mars,’ which I must have played maybe 20 times in a row,” says Rock. “I was completely intrigued.”

Rock, who was already writing articles and taking pictures of musicians for local publications, contacted Bowie’s publicist and went to see Bowie in concert.

“David looked like a space man," he says, "and then he performed, and I was completely blown away.”

Rock became Bowie’s official photographer. Soon after, his career as a rock 'n' roll photographer took off.

One of his favorite photo sessions was with Deborah Harry, the lead singer for the American group, Blondie.

“Nobody in rock 'n' roll ever photographed as fantastically as Debbie,” he says. “It was fair enough to call her the Marilyn Monroe of rock 'n' roll."

Two of Rock's shots of Harry are in the exhibit.

Iconic images

Over the years, Rock also gained fame for album covers he shot in the 1970s, including Lou Reed's “Transformer.”

Rock believes that album cover "defined Lou forever.”

Another of Rock's favorite photo sessions was with the legendary group, Queen. His photo of the group was used for the "Queen II" album, released in 1974.

While Queen was not well known at the time, Rock says, the cover “became their defining image.”

“Freddie Mercury had extraordinary talent,” he says, about the group's lead singer. “He was most comfortable at home in his dressing gown and slippers, having tea and a bit of a gossip.”

Many of Rock's photos of present-day superstars were taken before the singers became well known. In 1980, for example, he did test shots of a woman named Madonna.

"I think she was just a dancer at the time," he says. "She was young and raw.”

During a shoot with Lady Gaga in 2009, Rock says the singer surprised him with prophetic words.

“She actually says, ‘You know I’m going to be a very big star in the next few months.’"

New artists

These days, Rock isn't as driven as he used to be. He prefers a life of yoga, meditation and directing photo sessions.

He's currently working with the W Hotel, shooting portraits of musicians who perform there as part of the hotel's Symmetry Live series.

“Shooting for the 'W' has given me an opportunity to work with some great new artists,” he says, “including two of my favorites who blend rock ‘n' roll and hip-hop and dance."

One is Janelle Monae and the other is Theophilus London. Their photos are part of the exhibit.

Rock would like to be remembered as a man “who maybe came up with a few memorable images.”

The exhibit - with many memorable images - travels from Washington D.C. to other cities in the U.S.